From 451d7585a8bb1b9bec0d676ce3dece1923164e55 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Tue, 9 Jun 2009 20:28:34 -0400 Subject: Btrfs: add mount -o ssd_spread to spread allocations out Some SSDs perform best when reusing block numbers often, while others perform much better when clustering strictly allocates big chunks of unused space. The default mount -o ssd will find rough groupings of blocks where there are a bunch of free blocks that might have some allocated blocks mixed in. mount -o ssd_spread will make sure there are no allocated blocks mixed in. It should perform better on lower end SSDs. Signed-off-by: Chris Mason --- fs/btrfs/super.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) (limited to 'fs/btrfs/super.c') diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 22855a18eb48..7f5b2889949a 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -66,8 +66,8 @@ static void btrfs_put_super(struct super_block *sb) enum { Opt_degraded, Opt_subvol, Opt_device, Opt_nodatasum, Opt_nodatacow, Opt_max_extent, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, - Opt_ssd, Opt_nossd, Opt_thread_pool, Opt_noacl, Opt_compress, - Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_err, + Opt_ssd, Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, + Opt_compress, Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_err, }; static match_table_t tokens = { @@ -83,6 +83,7 @@ static match_table_t tokens = { {Opt_thread_pool, "thread_pool=%d"}, {Opt_compress, "compress"}, {Opt_ssd, "ssd"}, + {Opt_ssd_spread, "ssd_spread"}, {Opt_nossd, "nossd"}, {Opt_noacl, "noacl"}, {Opt_notreelog, "notreelog"}, @@ -174,9 +175,17 @@ int btrfs_parse_options(struct btrfs_root *root, char *options) printk(KERN_INFO "btrfs: use ssd allocation scheme\n"); btrfs_set_opt(info->mount_opt, SSD); break; + case Opt_ssd_spread: + printk(KERN_INFO "btrfs: use spread ssd " + "allocation scheme\n"); + btrfs_set_opt(info->mount_opt, SSD); + btrfs_set_opt(info->mount_opt, SSD_SPREAD); + break; case Opt_nossd: - printk(KERN_INFO "btrfs: not using ssd allocation scheme\n"); + printk(KERN_INFO "btrfs: not using ssd allocation " + "scheme\n"); btrfs_clear_opt(info->mount_opt, SSD); + btrfs_clear_opt(info->mount_opt, SSD_SPREAD); break; case Opt_nobarrier: printk(KERN_INFO "btrfs: turning off barriers\n"); @@ -429,7 +438,9 @@ static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs) seq_printf(seq, ",thread_pool=%d", info->thread_pool_size); if (btrfs_test_opt(root, COMPRESS)) seq_puts(seq, ",compress"); - if (btrfs_test_opt(root, SSD)) + if (btrfs_test_opt(root, SSD_SPREAD)) + seq_puts(seq, ",ssd_spread"); + else if (btrfs_test_opt(root, SSD)) seq_puts(seq, ",ssd"); if (btrfs_test_opt(root, NOTREELOG)) seq_puts(seq, ",notreelog"); -- cgit v1.2.3